ABSTRACT
[ ABSTRACT] AIM:To observe the changes of perilipin and adipose differentiation-related protein ( ADRP) du-ring the development of diabetes mellitus and to explore the effect of perilipin and ADRP on abnormal glucose metabolism with non-alcoholic fatty liver disease ( NAFLD) .METHODS:The rat model of impaired glucose tolerance ( IGT) was in-duced by feeding high-fat diet, and the type 2 diabetes mellitus (T2DM) model was induced by feeding high-fat diet for 4 weeks and intraperitoneally injecting streptozotocin.The morphological change of the liver tissue was observed under optical microscope.The serum contents of perilipin and ADRP were measured by ELISA.The mRNA expression of perilipin and ADRP in the liver tissues was detected by real-time PCR.The protein expression of ADRP in the liver tissues was deter-mined by Western blotting.RESULTS:HE staining showed steatosis in the liver of the rats in IGT group was more serious than that in T2DM group.The biochemical and the pathological processes of rat models were consistent with the clinical feature of related diseases.The serum content of perilipin had no difference among various groups.The mRNA expression of perilipin in IGT group and T2DM group was significantly higher than that in control group.Compared with IGT group, the mRNA expression of perilipin in T2DM group was significantly increased.The serum content of ADRP in T2DM group was significantly lower than that in control group.The mRNA and protein expression of ADRP in model groups was signifi-cantly lower than that in control group.Compared with IGT group, the mRNA expression of ADRP in T2DM group was sig-nificantly reduced.CONCLUSION: The serum content of ADRP plays a role in the development and progression of T2DM.It is negatively correlated with HOMA-IR.NAFLD occurs during progression of abnormal glucose metabolism in-duced by feeding high-fat diet.The development of abnormal glucose metabolism with NAFLD is probably related to the in-creased expression of perilipin and the reduced expression of ADRP.
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Purpose To investigate the expression of XBP-1s and ADRP in kidney of diabetic rats. Methods Diabetic rat models were successfully established by intraperitoneal injection of STZ. After two months rats were sacrificed and XBP-1s and ADRP were de-tected by immunohistochemistry and Western blot. Results XBP-1s and ADRP were located in renal tubular cells and increased by a-bout 2. 017 times and 1. 544 times in comparison with normal control rats (P<0. 05). Moreover, it was shown that high expression of XBP-1s was commonly accompanied with increased ADRP by Pearson correlation analysis and the correlation coefficient was 0. 723 (P<0. 05). Conclusion The increased XBP-1s may cause the up-regulation of ADRP in the kidney of diabetic rats.
ABSTRACT
BACKGROUND: Skeletal muscle is the most important tissue contributing to insulin resistance. Several studies have shown that accumulation of intramyocellular lipid is associated with the development of insulin resistance. Thus, proteins involved in lipid transport, storage and metabolism might also be involved in insulin action in skeletal muscle. Adipose differentiation-related protein (ADRP), which is localized at the surface of lipid droplets, is known to be regulated by peroxisome proliferator activated receptor gamma (PPARgamma). However, it is not known whether ADRP plays a role in regulating glucose uptake and insulin action in skeletal muscle. METHODS: ADRP expression in skeletal muscle was measured by RT-PCR and western blot in db/db mice with and without PPARgamma agonist. The effect of PPARgamma agonist or high lipid concentration (0.4% intralipos) on ADRP expression was also obtained in cultured human skeletal muscle cells. Glucose uptake was measured when ADRP was down-regulated with siRNA or when ADRP was overexpressed with adenovirus. RESULTS: ADRP expression increased in the skeletal muscle of db/db mice in comparison with normal controls and tended to increase with the treatment of PPARgamma agonist. In cultured human skeletal muscle cells, the treatment of PPARgamma agonist or high lipid concentration increased ADRP expression. siADRP treatment decreased both basal and insulin-stimulated glucose uptake whereas ADRP overexpression increased glucose uptake in cultured human skeletal muscle cells. CONCLUSION: ADRP expression in skeletal muscle is increased by PPARgamma agonist or exposure to high lipid concentration. In these conditions, increased ADRP contributed to increase glucose uptake. These results suggest that insulin-sensitizing effects of PPARgamma are at least partially achieved by the increase of ADRP expression, and ADRP has a protective effect against intramyocellular lipid-induced insulin resistance.